In such apparatus, the object recognition device is usually arranged above the workpieces to be picked in order to allow an accurate detection of the position of the workpieces to be picked. However, the gripper for picking the workpieces also has to work in this region.
The object recognition device is therefore partly arranged at the gripper itself so that the object recognition device is moved along with the gripper. However, the evaluation of the data is made considerably more difficult by this. In addition problems arise with respect to the stability of the arrangement since the sensor can hereby easily collide with interfering edges.
It is the object of the present invention to provide an apparatus for the automated detection and removal of workpieces whose object recognition device has a high accuracy in the detection of workpieces with a simultaneously high security against disturbance.
This object is achieved in accordance with the invention by an apparatus for the automated removal of workpieces arranged in a container, comprising a first object recognition device for detecting the workpieces and a first gripper for picking and removing the workpieces from the container; and a control for evaluating the data of the first object recognition device, for path planning and for controlling the first gripper, characterized by an intermediate station on which the first gripper places the workpieces after the removal from the container and a positioning apparatus which positions the work pieces more accurately and/or singularizes the workpieces starting from the intermediate station.
The present invention shows an apparatus for the automated detection and removal of workpieces comprising an object recognition device for detecting the workpieces, a gripper for picking the workpieces and a control for evaluating the data of the object detection device and for controlling the gripper. The control can in this respect in particular comprise an evaluation device for evaluating the data, a track planning module for track planning and a control unit for controlling the gripper. In accordance with the invention, the object recognition device is arranged at a travel arrangement by which it can be traveled from a position of rest into at least one measuring position and back.
In accordance with the invention, the object recognition device is thus still installed separately from the gripper at the apparatus and is not moved along with it, but it does have its own travel arrangement which allows a traveling of the object recognition device. The detection of the workpieces in a position ideal for this purpose can hereby take place without the object recognition device coming into conflict with the gripper for picking the workpiece.
The apparatus in accordance with the invention can in this respect in particular serve the handling of randomly arranged workpieces since the position of the workpieces can be determined by a suitable object recognition device and therefore does not have to be known in advance. The apparatus can naturally, however, also be used when the workpieces are already arranged in a certain order.
The object recognition device is in this respect preferably located in its position of rest outside a collision region with the gripper. The gripper hereby no longer has to take account of the object recognition device on the picking of the workpieces since said object recognition device is located outside the collision region of the gripper and thus does not present any relevant interference edge.
Provision can furthermore be made that the object recognition device is located in its measuring position within a collision region with the gripper. The object recognition device can hereby be positioned closer at the workpieces which it is intended to detect, which substantially increases the accuracy of the detection.
The object recognition device can in this respect in particular be located in its measuring position above a removal region of the workpieces by the gripper, for example above or within a container or a placement surface or transport surface for the workpieces.
The control is in this respect advantageously configured so that the movement of the object recognition device is controlled in a synchronized fashion with the removal movement of the gripper. It can hereby be ensured that no collisions arise between the object recognition device and the gripper.
The object recognition device can in particular be traveled into the measuring position during a placing movement of the gripper and can be traveled into the position of rest before a picking up movement of the gripper to pick a workpiece. The detection of the workpieces thus always takes place when the gripper is just placing down a workpiece. During the picking up of a workpiece, the object recognition device is, in contrast, located in its position of rest and thus advantageously outside the collision region of the gripper.
In a first embodiment of the present invention, the movement of the object recognition device takes place at least also in the horizontal direction. The object recognition device can in this respect in particular be traveled laterally over a removal region of the workpieces in order thus to reach an ideal position for the detection of the workpieces.
Alternatively or additionally, such a movement can also take place in a vertical direction.
In accordance with the invention, any desired system which allows the identification of the workpieces and the selection of a workpiece suitable for picking can be used as an object detection device for detecting the workpieces.
The detection of the workpieces in this respect typically comprises a data logging by a measurement process. An identification of the individual workpieces in the detection zone from which a workpiece suitable for picking is selected then takes place by evaluating the data. The movement of the gripper or of the gripping arm moving it is planned on the basis of the positional data of this workpiece. In this respect, a collision check can be carried out so that a movement routine is selected in which the gripper or the gripping arm does not collide with interfering edges such as the other workpieces or the side walls of the container. The gripper or the gripping arm is then controlled using the data thus calculated.
If the object recognition device is locate above the collision region of the gripper in its position of rest, the object recognition device does not have to be taken into account as an interfering edge in the collision check in accordance with the invention in this respect. The gripper in this respect advantageously only travels into the removal region when the object recognition device was traveled out of the collision region with the gripper. Alternatively, a synchronized movement of the object recognition device in the collision region with the gripper is also conceivable during the picking procedure.
In this respect, in particular optical sensors are used as the object recognition device, with in particular laser sensors and/or image sensors being able to be used. The sensors can in this respect work two-dimensionally, two-and-half-dimensionally and three-dimensionally. A laser scanner, in particular a 3D laser scanner, is particularly preferably used in this respect.
Provision can be made in accordance with the invention in this respect that the object recognition device includes a sensor which is pivoted for detecting the workpieces in a measuring position of the object recognition device to detect the removal region. Such a pivoting of the sensor in the measuring position in this respect allows a better detection of the workpieces in the removal region. It can in particular also thus be avoided or the fact reduced that the side walls of a container in which the workpieces are received and/or the workpieces themselves cast shadows.
The sensor can in particular be arranged approximately centrally above the removal region in a measuring position.
Alternatively or additionally, it is conceivable to travel the sensor over the removal region during the measurement, for which purpose in particular the travel arrangement can be used which is anyway present.
The object recognition device in this respect in particular comprises a laser sensor. The laser sensor can in this respect in particular be a laser scanner. It is advantageously pivoted and/or traveled over the removal region as described above.
Provision can be made in a further embodiment of the present invention that the movement of the object recognition device takes place at least also in the vertical direction. On the one hand, such a movement in the vertical direction can also allow a withdrawal of the object recognition device from the collision region with the gripper. Alternatively or additionally, such a movement in the vertical direction allows the maintenance of an unchanging accuracy in the detection of the workpieces.
Provision is particularly preferably made in this respect to reposition the object recognition device in a following movement as the filling level of the removal region falls in the vertical direction. It can in particular be ensured by the vertical following movement of the object recognition device that the object recognition device is always arranged in a predefined distance range from the topmost workpieces in the removal region when the object recognition device is located in a measuring position.
An unchanging quality of the logged data is hereby ensured over the total emptying cycle of, for example, a container. This is in particular relevant when a container having a certain height is used from which the workpieces are to be removed.
Provision can be made in this respect that the object recognition device is lowered down and into the interior of a container.
In a further embodiment of the present invention, a horizontal travel movement of the object recognition device can be combined with a vertical travel movement. The object recognition device can thus, for example, be traveled horizontally over the removal region and can there be traveled in a vertical direction into a measuring position.
Provision can furthermore be made in accordance with the invention that the object recognition device comprises a photosensor and in particular a camera. A detection of the workpieces by such a photosensor is also conceivable. Furthermore, in this respect, a plurality of photosensors and/or cameras and/or a combination of a 3D laser scanner and a photoscanner can also be used.
If a photosensor, and in particular a camera, is used, it is conceivable to adjust the focus of the sensor in a following manner as the filling level of the removal region falls. In this respect, in particular a focus of an optical system of the sensor can be correspondingly controlled. An unchanging detection quality over the total removal process can also hereby be achieved.
The apparatus in accordance with the invention is particularly preferably used for the automated removal of workpieces from a container.
Alternatively, the object recognition device can, however, also be used to detect workpieces on an intermediate station on which a gripper places workpieces after a removal from a container. The object recognition device can in this respect also be used to control a further gripper which takes the workpieces off from the intermediate station again.
Provision can furthermore be made that the object recognition device is traveled closer to a part region of the detection region to detect workpieces located there more accurately. For example, in this respect, a first measuring position can be provided for the normal detection of the total detection region. If a more accurate detection is required, the object recognition device can be traveled from this first measuring position into a second measuring position in which admittedly the total detection region is no longer detected, but the now detected part region can be detected with a higher accuracy. For example, the object recognition device can in this respect be traveled to a workpiece which is difficult to detect or can be used for checking a workpiece for the satisfaction of predefined criteria. The second measuring position can in particular depend on the position of a workpiece to be detected even more accurately.
The present invention furthermore comprises a method for the automated detection and removal of workpieces which comprises the steps                detecting the workpieces using an object recognition device; and        picking the workpieces using a gripper.        
Provision is made in accordance with the invention that the object recognition device for detecting the workpieces is traveled from a position of rest into at least one measuring position. Provision can furthermore be made that the object recognition device is traveled back from the measuring position into the position of rest for picking a workpiece.
The method in accordance with the invention is advantageously carried out in this respect as has already been described with respect to the apparatus in accordance with the invention. The method in accordance with the invention in particular takes place in this respect using an apparatus as was described above.
The present invention furthermore comprises a computer program for carrying out a method in accordance with the invention. The computer program in this respect in particular comprises commands which a method in accordance with the invention implements for the automated handling of workpieces. The computer program in accordance with the invention in particular serves the implementation of a control for an apparatus as described above in this respect.
The apparatus in accordance with the invention can furthermore be a component of an apparatus for the automated removal of workpieces arranged in a container, which apparatus comprises a first object recognition device for detecting the workpieces and a first gripper for picking and removing the workpieces from the container as well as a control for evaluating the data of the first object recognition device, for track planning and for controlling the first gripper. Furthermore, in this respect an intermediate station can be provided on which the first gripper places the workpiece after the removal from the container and a positioning apparatus which positions the workpiece more accurately starting from the intermediate station and/or singularizes them.
In this respect in particular a gripper can be used as the positioning apparatus, with it advantageously being a second gripper. In accordance with the invention, the first gripper and/or the second gripper can be moved via automatically controlled adjustment axes of a gripping arm. In a first embodiment variant, the first gripper and the second gripper can in this respect be arranged at a common gripping arm and can be moved via it. The first and second grippers are, however, preferably arranged at separate gripping arms and can thus be moved independently of one another.
A second object recognition device can preferably also be arranged on the intermediate station to detect workpieces placed on the intermediate station and to control a gripper of the positioning apparatus which picks up the workpieces from the intermediate station.
In this respect, the travelable object recognition device in accordance with the invention can in particular be the first object recognition device of such an apparatus.
Alternatively or additionally, a travelable object recognition device in accordance with the invention can also be used as a second object recognition device arranged on the intermediate station.
In this respect, the first gripper for picking the workpiece is advantageously a magnetic and/or pneumatic gripper, in particular a magnetic gripper. Further advantageously, the gripper of the positioning apparatus is a mechanical gripper.
In this respect, the workpieces can be randomly placed on the intermediate station by the first gripper.
The workpieces can in particular be dropped onto the intermediate station from a certain height by the first gripper. A slanted plane is advantageously provided in this respect onto which the workpieces are dropped.
Further advantageously, the intermediate station comprises a transport device by which the workpieces are transported from a placing region to a removal region. The second object detection device is advantageously arranged above the transport device in the removal region.
All the steps in the handling of the workpieces advantageously take place by the method in accordance with the invention and/or by the apparatus in accordance with the invention in a fully automated manner and without a user intervention being necessary.